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Desert FrogletCrinia deserticola

The Desert Froglet (Crinia deserticola) is a small Myobatrachid from with a large range across the northern region of Australia. It is a frog of open woodlands and swampy areas. These frogs were recorded in swampy grassland and woodland near the entrance to the Mareebra Swamp Environmental Park in Queensland in December 2014. I heard them calling day and night.Their call is a strange metallic, insect-like two syllable call. It could be described as "di-dink", although the two syllables are hard to distinguishHere is a single call from one individual -

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But when we look at the spectrogram for that call, we see it is actually two separate notes. The carrier (dominant) frequency of the call is somewhere between 4.2 and 4.3 kHz. The problem is that the two notes are given so rapidly, that they can't really be distinguished by the human ear/brain. The space between the notes here is approximately 1/100th of a second!

But if we slow down the speed of the recording by 50%, we can discriminate both notes of this call as distinct. This is exactly the same recording shown above slowed down 50% (with the pitch kept constant) -

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They are very difficult to locate by their calls and although I heard a large number of them, I was unable to find a single individual for a photo.Here is a recording of a small group of individuals -

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and here is a larger chorus. This file had to be edited to remove the calls of several other species, resulting a slightly "tinny" recording.

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